1. Field of the Invention
The present invention relates to a semiconductor IC circuit device having dummy wires and a method for manufacturing the same, both of which are employed for a multi-layer type semiconductor integrated circuit to be formed by an automatic array connection system, such as a standard cell structure and a gate array structure.
2. Description of the Related Art
Dummy wires have conventionally been employed:
(1) to prevent an unevenness (a step) on the surface of a semiconductor integrated circuit resulting from a different wire density at a respective area in the same connection layer or to offer a countermeasure against a "loading effect" which is produced in the case where, if a single wire is provided in a broader connection area, it is broken apart due to a corrosion caused by etching--see Published Unexamined Japanese patent application No. 60-119749; and
(2) to correct a wrongly connected line or layer in which case the dummy wires are arranged, at a given connection layer, for correction only and, if a semi-conductor device manufactured is defective, are employed to correct a defective spot or spots--Published Unexamined Japanese Patent Publication 59-198796, 61-125045 and 62-206855.
FIG. 1 is a plan view showing an IC pattern having conventional dummy wires. In FIG. 1, reference numeral 1 shows a first connection layer; 2, a second connection layer; 3, a connection through hole or a contact hole; 4, dummy wires; 5, an array of cells (it is assumed that they are formed by a standard cell system); 6, an internal power source terminal V.sub.DD ; 7, an internal power source terminal V.sub.SS ; and 8, cell-to-cell wires.
Conventional dummy wires have proved ineffective in both preventing an unevenness (a step) on the surface of integrated circuits while offering a countermeasure against a loading effect, and correcting a wiring or connection error, if any. In order to prevent such an uneven surface and to provide a countermeasure against such a loading effect, dummy wires 4 are used such that, as shown in FIG. 1, they have a proper width to serve the purpose for which they are formed. The dummy wires cannot be utilized in the conventional semiconductor devices due in part to a "not fixed" width and in part to its own limited use in particular. If they are initially built in a semiconductor IC device so as to correct a connection error, they sometimes prove fruitless for such a purpose as in the aforementioned case.